The present invention relates to an apparatus for raising a liquid to a given temperature and for controlling and regulating in a constant and accurate manner the temperature to which the said liquid has been raised.
This apparatus can be used for heating each of the liquid phases entering each of the ends of a liquid-liquid extraction column and for accurately regulating the temperature thereof.
It is known that an aqueous acid solution is used for example for reextracting uranium or plutonium previously fixed by an organic solution such as tributyl phosphate or trilauryl amine, said liquid - liquid reextraction taking place in a column in which the two solutions are in countercurrent. In such liquid - liquid extractions columns it is necessary that each of the two liquid phases introduced respectively at the lower end and at the upper end of the extraction column at a given flow rate is at a particular temperature and that said temperature remains as constant as possible to within a few tenths of a .degree.C.
To raise each of the phases to the desired temperature and to maintain said temperature constant a heating element, such as an electrical resistor has been brought into direct contact with each of these phases. However, it has been found that in this case there is a deterioration of the liquid phases which is liable to seriously prejudice the quality of the chemical exchangers during the exchange cycles.